A process I read said to mix isopropol alcohol with 5% oil, remove the lenses, then put the glassless shutter in the ultrasonic cleaner for a few minutes. Frequent sloshing the shutter helps.

Low pressure air (canned air from a distance?) was used to dry the assembled parts. As the alcohol dried, a very thin film of oil was left on the parts. Wiping the shutter and aperture blades dry with a cotton swab removed enough remaining oil from these parts. But some oil remained where it was needed.

Some shutter brands use hard rubber for the shutter and or aperture blades. Petroleum products will damage these blades.

Flash sync sockets have plastic insulators in them that can be damaged by petroleum products. Oil can conduct electrical current and cause a high resistance short in the flash sync circuit.

Alcohol may contain water which can cause corrosion in slow to dry areas.
Although I occasionally use Alcohol to clean some parts I do not soak a complete shutter in Alcohol and I dry each piece upon once cleaned.

Cotton leaves very fine fibers behind regardless of how careful one is when using it on metal parts. These fibers are very time consuming to remove.

An ultrasonic cleaner with a plastic/rubber safe cleaner that will evaporate quickly will work well for cleaning a shutter but rarely is a shutter so gummed up that such a cleaning will be required.

Oil on areas of the shutter that do not need lubricating and are not accessible unless the shutter is disassembled can attract and retain dust._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

YES Bart
I do use the ultrasonic cleaner on shutters ! got it at http://www.harborfreight.com/
I have the 2.5 Liter Ultrasonic Cleaner right now on sale $69.99
I have tried different things THE isopropol alcohol with 5% oil dont work that good
on most the I have tried it on!! watch repairman use stuff with Ammonia in it all the time
its like $35. a Gal. have not yet got any to try as my watch repairman is all most out
and had not ordered yet but will get me a Gal. soon to try but it works great on watch !
now I have tried on motorcycle Carbs 50/50 simple green will work
NOW a lot of people use lighter fluid to clean shutter with out an ultrasonic cleaner
it is about the best thing to use last as it will dry out good
Now I have used it in my ultrasonic cleaner but some shutters are really in bad need
of a good cleaning ! Now I have one shutter that I have NEVER got clean yet & it mite
go in the trash some time yet But I am still trying different thing to clean it with!!

BUT most shutters that I have cleaned in KINGSFORD Charcoal Lighter Fluid works
good my ultrasonic cleaner has a 4 minutes timer so I have to start it about 7 times
to run about 30 minutes ! it also has heat that helps to use it too
IF you use isopropol alcohol most that you buy is 70* water you have to get it DRY
so I would use Lighter Fluid after the alcohol rinse out good with clean Lighter Fluid

you could give me that stubborn shutter instead of trashing it. Lighter fluid will destroy rubber/plastic parts used in shutters, sounds like you've been lucky so far._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

so far have not had any go bad
but this one and it was so nasty to start with
right now it in the ultrasonic cleaner with Ammonia & water
what ever was in it it gets gumer the more I try to clean no mater
what I use

The grease/oil is now the consistency of dried concrete. Fresh oil and solvents turn the dried grease to a thick, sticky paste. The only solution I have found is to fully dismantle the shutter, scrape the goo off the parts and out of the crevices, soak and flush until no trace of the old stuff remains, then apply fresh lubrication and reassemble.

Use a Digital camera with Macro Mode, take pictures of each stage of the cover removal, the internal works fully assembled, and after each part is removed verifying that the pictures are in focus and show the details clearly before moving to the next part/stage. This makes reassembly much easier._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.